VanDusen Botanical Garden Visitor Centre
Vancouver, British Columbia, Canada / Perkins+Will




At the center of the VanDusen Botanical Garden Visitor Centre’s multipetaled structure is a circular space topped by a daylit oculus. Unlike its better-known predecessor in Rome’s Pantheon, this round rooftop opening is protected from the elements, and its diameter varies from about 15 feet at its base to just under 10 feet at its top.

Below the conical skylight that protrudes through the building’s green roof is a multihued, powdercoated, perforated aluminum cone that serves as a heat sink. The heat sink’s form was “shaped by the sun,” Busby says. “The color is darker in the areas that are only hit by the summer sun—since you need to maximize the temperature differential to make the chimney effect work.” These darker areas are at the base of the heat sink, and are hit by the rays of the summer sun, increasing the temperature in the oculus to encourage airflow.

On summer days, operable windows in the sides of the skylight open and the heat-sink construct draws warm air through the building and exhausts it out through the vents. To the casual observer, the heat sink appears to be just another sculptural form in a building that’s packed with—indeed, composed of—them. But the multivalent device provides both a centerpiece to the visitor center and another place to start a conversation about how to make buildings work better with nature—an essential part of VanDusen’s mission and Busby’s sophisticated sustainable architecture.